This invention relates to acetylenic aryl sulfonamide hydroxamic acids which act as inhibitors of TNF-xcex1 converting enzyme (TACE). The compounds of the present invention are useful in disease conditions mediated by TNF-xcex1, such as rheumatoid arthritis, osteoarthritis, sepsis, AIDS, ulcerative colitis, multiple sclerosis, Crohn""s disease and degenerative cartilage loss.
TNF-xcex1 converting enzyme (TACE) catalyzes the formation of TNF-xcex1 from membrane bound TNF-xcex1 precursor protein. TNF-xcex1 is a pro-inflammatory cytokine that is believed to have a role in rheumatoid arthritis [Shire, M. G.; Muller, G. W. Exp. Opin. Ther. Patents 1998, 8(5), 531; Grossman, J. M.; Brahn, E. J. Women""s Health 1997, 6(6), 627; Isomaki, P.; Punnonen, J. Ann. Med. 1997, 29, 499; Camussi, G.; Lupia, E. Drugs, 1998, 55(5), 613.] septic shock [Mathison, et. al. J. Clin. Invest. 1988, 81, 1925; Miethke, et. al. J. Exp. Med. 1992, 175, 91.], graft rejection [Piguet, P. F.; Grau, G. E.; et. al. J. Exp. Med. 1987, 166, 1280.], cachexia [Beutler, B.; Cerami, A. Ann. Rev. Biochem. 1988, 57, 505.], anorexia, inflammation [Ksontini, R,; MacKay, S. L. D.; Moldawer, L. L. Arch. Surg. 1998, 133, 558.], congestive heart failure [Packer, M. Circulation, 1995, 92(6), 1379; Ferrari, R.; Bachetti, T.; et. al. Circulation, 1995, 92(6), 1479.], post-ischaemic reperfusion injury, inflammatory disease of the central nervous system, inflammatory bowel disease, insulin resistance [Hotamisligil, G. S.; Shargill, N. S.; Spiegelman, B. M.; et. al. Science, 1993, 259, 87.] and HIV infection [Peterson, P. K.; Gekker, G.; et. al. J. Clin. Invest. 1992, 89, 574; Pallares-Trujillo, J.; Lopez-Soriano, F. J. Argiles, J. M. Med. Res. Reviews, 1995, 15(6), 533.]], in addition to its well-documented antitumor properties [Old, L. Science, 1985, 230, 630.]. For example, research with anti-TNF-xcex1 ntibodies and transgenic animals has demonstrated that blocking the formation of TNF-xcex1 inhibits the progression of arthritis [Rankin, E. C.; Choy, E. H.; Kassimos, D.; Kingsley, G. H.; Sopwith, A. M.; Isenberg, D. A.; Panayi, G. S. Br. J. Rheumatol. 1995, 34, 334; Pharmaprojects, 1996, Therapeutic Updates 17 (October), au197-M2Z.]. This observation has recently been extended to humans as well as described in xe2x80x9cTNF-xcex1 in Human Diseasesxe2x80x9d, Current Pharmaceutical Design, 1996, 2, 662.
It is expected that small molecule inhibitors of TACE would have the potential for treating a variety of disease states. Although a variety of TACE inhibitors are known, many of these molecules are peptidic and peptide-like which suffer from bioavailability and pharmacokinetic problems. In addition, many of these molecules are non-selective, being potent inhibitors of matrix metalloproteinases and, in particular, MMP-1. Inhibition of MMP-1 (collagenase 1) has been postulated to cause joint pain in clinical trials of MMP inhibitors [Scrip, 1998, 2349, 20] Long acting, selective, orally bioavailable non-peptide inhibitors of TACE would thus be highly desirable for the treatment of the disease states discussed above.
U.S. Pat. Nos. 5,455,258, 5,506,242, 5,552,419, 5,770,624, 5,804,593, and 5,817,822 as well as European patent application EP606,046A1 and WIPO international publications WO9600214 and WO9722587 disclose non-peptide inhibitors of matrix metalloproteinases and/or TACE of which the aryl sulfonamide hydroxamic acid shown below is representative. Additional publications disclosing sulfonamide based MMP inhibitors which are variants of the sulfonamide-hydroxamate shown below, or the analogous sulfonamide-carboxylates, are European patent applications EP-757037-A1 and EP-757984-A1 and WIPO international publications WO9535275, WO9535276, WO9627583, WO9719068, WO9727174, WO9745402, WO9807697, WO9831664, WO9833768, WO9839313, WO9839329, WO9842659 and WO9843963. The discovery of this type of MMP inhibitor is further detailed by MacPherson, et. al. in J. Med. Chem., 1997, 40, 2525 and Tamura, et. al. in J. Med. Chem. 1998, 41, 640. 
Publications disclosing xcex2-sulfonamide-hydroxamate inhibitors of MMPs and/or TACE in which the carbon alpha to the hydroxamic acid has been joined in a ring to the sulfonamide nitrogen, as shown below, include U.S. Pat. No. 5,753,653, WIPO international publications WO9633172, WO9720824, WO9827069, WO9808815, WO9808822, WO9808823, WO9808825, WO9834918, WO9808827, Levin, et. al. Bioorg. and Med. Chem. Letters 1998, 8, 2657 and Pikul, et. al. J. Med. Chem. 1998, 41, 3568. 
The patent applications DE19,542,189-A1, WO9718194, and EP803505 disclose additional examples of cyclic sulfonamides as MMP and/or TACE inhibitors. In this case the sulfonamide-containing ring is fused to a aromatic or heteroaromatic ring. 
Examples of sulfonamide hydroxamic acid MMP/TACE inhibitors in which a 2 carbon chain separates the hydroxamic acid and the sulfonamide nitrogen, as shown below, are disclosed in WIPO international publications WO9816503, WO9816506, WO9816514 and WO9816520 and U.S. Pat. No. 5,776,961. 
Analogous to the sulfonamides are the phosphinic acid amide hydroxamic acid MMP/TACE inhibitors, exemplified by the structure below, which have been disclosed in WIPO international publication WO9808853. 
Sulfonamide MMP/TACE inhibitors in which a thiol is the zinc chelating group, as shown below, have been disclosed in WIPO international application 9803166. 
It is an object of this invention to provide aryl sulfonamide hydroxamic acid MMP/TACE inhibitors in which the sulfonyl aryl group is para-substituted with a substituted butynyl moiety or a propargylic ether, amine or sulfide.